1. Field of the Invention
The present invention relates to a semiconductor device having a through electrode and a method of manufacturing the semiconductor device.
2. Description of the Background Art
Referring to FIG. 43, a semiconductor device 50 is electrically connected to semiconductor devices 60 and 70 by wire bonds 32 and 32. Semiconductor devices 60 and 70 are electrically connected to each other as well by wire bond 32.
Semiconductor device 50 is for example an integrated circuit (ASIC: Application Specific Integrated Circuit). Referring to FIG. 44, semiconductor device 50 includes a semiconductor substrate 1 having a first main surface 10 and a second main surface 20. Semiconductor device 50 also includes a semiconductor element portion 5 and a terminal 32a to be wire-bonded.
Semiconductor devices 60 and 70 are each for example a semiconductor acceleration sensor having a thin-film structure. Referring to FIG. 45, semiconductor device 60 includes a Si substrate 61. Si substrate 61 is held between cap portions 62a and 62b. In Si substrate 61, support portions 63a and 63b and floating portions 64a and 64b are formed.
Support portions 63a and 63b are connected to cap portions 62a and 62b respectively. Semiconductor device 60 includes a terminal 32b to be wire-bonded. Japanese Patent Laying-Open No. 2000-187041 discloses a configuration similar to that of semiconductor device 60.
Semiconductor device 70 is configured similarly to above-described semiconductor device 60. Semiconductor devices 50, 60 and 70 as described above are arranged on substantially the same plane (see FIG. 43), and therefore, a two-dimensional area is necessary for mounting semiconductor devices 50, 60 and 70.
In contrast, there is a technique of three-dimensionally mounting semiconductor devices 50, 60 and 70 by vertically stacking semiconductor devices 50, 60 and 70, which will now be described. Referring to FIG. 46, semiconductor devices 50, 60 and 70 are stacked in the vertical direction. Respective semiconductor elements of semiconductor devices 50, 60 and 70 are electrically connected to each other by electrodes 30a and 30c that are each a through electrode.
In FIG. 46, each semiconductor device is shown schematically for illustrative convenience, and details of the semiconductor elements are not given. Each semiconductor element is shown in detail in FIG. 47.
A detailed description will be given with reference to FIG. 47. In order to electrically connect a terminal electrode 31a which is electrically connected to a semiconductor element portion of semiconductor device 50, and a terminal electrode 31c which is electrically connected to a semiconductor element portion of semiconductor device 60, semiconductor device 60 includes electrode 30c extending therethrough in the direction of the thickness of semiconductor device 60. Electrode 30c is thus a through electrode. Between semiconductor devices 50 and 60, an electrically conductive bump 33c is provided for electrically connecting electrode 30c and terminal electrode 31a. 
In order to electrically connect a terminal electrode 31e which is electrically connected to a semiconductor element portion of semiconductor device 70 and terminal electrode 31a of semiconductor device 50, semiconductor device 50 includes electrode 30a extending therethrough in the direction of the thickness of semiconductor device 50. Electrode 30a is thus a through electrode. Between semiconductor devices 50 and 70, an electrically conductive bump 33a is provided for electrically connecting electrode 30a and terminal electrode 31e. Thus, semiconductor devices 50 and 60 are electrically connected, and semiconductor devices 70 and 50 are electrically connected.
Semiconductor device 60 also includes another electrode 30d that is a through electrode for connecting respective semiconductor elements of semiconductor devices 50 and 60. Electrode 30d electrically connects a terminal electrode 31d which is electrically connected to another semiconductor element portion of semiconductor device 60, and a bump 33d provided between semiconductor devices 60 and 50.
Similarly, semiconductor device 50 includes another electrode 30b that is a through electrode for connecting respective semiconductor elements of semiconductor devices 50 and 70. Electrode 30b electrically connects a terminal electrode 31b which is electrically connected to another semiconductor element portion of semiconductor device 50, and a bump 33b provided between semiconductor devices 50 and 70.
The technique of vertically stacking semiconductor devices 50, 60 and 70 so that the semiconductor devices are three-dimensionally mounted is also disclosed in Japanese Patent Laying-Open Nos. 2004-152811, 2003-046057 and 2004-200547. A technique concerning the through electrode is also disclosed in Japanese Patent Laying-Open Nos. 2002-237468, 2001-044197 and 2007-096233.